Michéal Martin took aim at Sinn Fein today, describing them as a "mafia organisation" that operate under "a vow of omerta".
The Fianna Fail leader made his comments on Newstalk Lunchtime, while disputing the contention that Gerry Adam's party have robbed Fianna Fail of their title as the official Republican party.
"Listen, Sinn Fein are a mafia organisation, they use a vow of omerta to operate.
"If you look at the child sex abuse scandals of Mairia Cahill and Paudie McGahon and the subsequent denials you can see how these stories were covered up.
"Later they admitted using internal courts or whatever," he told host Jonathan Healy.
Mr Martin said that he had met with the parents of Paul Quinn who was beaten to death by an IRA gang in Co. Monagahan in 2007.
"Those people broke every single bone in his body," Mr. Martin said.
The Cork South Central TD also strongly refuted a suggestion that Sinn Fein are leading the protests in Dublin 1 in relation to the 'Save Moore Street' campaign.
"Standing with a megaphone on Moore Street isn't the same as creating substantive policies.
"Sinn Fein also stand outside police stations with megaphones when one of their own has been arrested," he said.